\subsubsection*{Travel}
A travel is used to represent the start and final stop location of a trip. The attribute, totaltraveltime, is used for storing the total number of hours and minutes that will be used for the entire trip, starting from the first departure airport to the final destination airport, including all the connecting flights. The attribute, numberofstops, is used for storing total the number of connecting flights in a travel.

\subsubsection*{Flight}
A flight is used to represent a particular route. The same route can be repeated multiple times in a week or month. Attributes timeofdeparture and timeofarrival are used for storing the different dates and times that a particular route is repeated within the same week or month. A physical Airplane information is retrieved via a foreign key (idairplane) to Airplane table. Airport information is retrieved via a foreign key (idairport) to Airport table. The attribute traveltime stores the total number of hours that will be used for a particular route. 

\subsubsection*{TravelFlight}
TravelFlight contains the id's of all flights that are part of a travel. It combines idflight and idtravel as primary key. The same flight can be part of different travels. 




